DTHitPairForFit Class Reference

#include <DTHitPairForFit.h>

Public Member Functions
float	digiTime () const
	Returns the time of the corresponding digi. More...
	DTHitPairForFit (const DTRecHit1DPair &pair, const DTSuperLayer &sl, const edm::ESHandle< DTGeometry > &dtGeom)
	Constructor. More...
const DTWireId &	id () const
	Returns the Id of the wire on which the rechit rely. More...
std::pair< bool, bool >	isCompatible (const LocalPoint &posIni, const LocalVector &dirIni) const
LocalPoint	leftPos () const
	Returns the position in the layer r.f. of the left rechit. More...
LocalPoint	localPosition (DTEnums::DTCellSide s) const
	Returns the local position in the layer. More...
LocalError	localPositionError () const
bool	operator< (const DTHitPairForFit &hit) const
	define the order by increasing z More...
bool	operator== (const DTHitPairForFit &hit) const
LocalPoint	rightPos () const
	Returns the position in the layer r.f. of the right rechit. More...
	~DTHitPairForFit ()
	Destructor. More...

Private Attributes
float	theDigiTime
LocalError	theError
LocalPoint	theLeftPos
LocalPoint	theRightPos
DTWireId	theWireId

Detailed Description

Hit pair used for the segments fit

This class is useful for segment fitting, which is done in SL or Chamber reference frame, while the DT hits live on the layer.

Author

Stefano Lacaprara - INFN Legnaro stefa.nosp@m.no.l.nosp@m.acapr.nosp@m.ara@.nosp@m.pd.in.nosp@m.fn.i.nosp@m.t

Riccardo Bellan - INFN TO ricca.nosp@m.rdo..nosp@m.bella.nosp@m.n@ce.nosp@m.rn.ch

Definition at line 31 of file DTHitPairForFit.h.

Constructor & Destructor Documentation

DTHitPairForFit::DTHitPairForFit	(	const DTRecHit1DPair &	pair,
		const DTSuperLayer &	sl,
		const edm::ESHandle< DTGeometry > &	dtGeom
	)

Constructor.

Definition at line 20 of file DTHitPairForFit.cc.

References DTRecHit1DPair::componentRecHit(), DTRecHit1DPair::digiTime(), DTGeometry::layer(), DTEnums::Left, DTRecHit1D::localPosition(), DTRecHit1D::localPositionError(), DTEnums::Right, GeomDet::toGlobal(), GeomDet::toLocal(), and DTRecHit1DPair::wireId().

                                                                        {

  theWireId = pair.wireId();
  theDigiTime = pair.digiTime();
  
  const DTLayer* layer = dtGeom->layer(theWireId.layerId());

  // transform the Local position in Layer-rf in a SL local position
  theLeftPos =
    sl.toLocal(layer->toGlobal(pair.componentRecHit(DTEnums::Left)->localPosition()));
  theRightPos =
    sl.toLocal(layer->toGlobal(pair.componentRecHit(DTEnums::Right)->localPosition()));

  // TODO how do I transform an error from local to global?
  theError = pair.componentRecHit(DTEnums::Left)->localPositionError();
  // theError =
  //   layer->surface().toLocal(sl.surface().toGlobal(pair.componentRecHit(DTEnums::Left)->localPositionError()));
  
}

DTHitPairForFit::~DTHitPairForFit

(

)

Destructor.

Definition at line 43 of file DTHitPairForFit.cc.

                                  {
}

Member Function Documentation

float DTHitPairForFit::digiTime ( ) const

inline

Returns the time of the corresponding digi.

Definition at line 61 of file DTHitPairForFit.h.

References isCompatible(), operator<(), operator==(), and theDigiTime.

Referenced by operator==().

{return theDigiTime;}

const DTWireId& DTHitPairForFit::id ( void  ) const

inline

Returns the Id of the wire on which the rechit rely.

Definition at line 58 of file DTHitPairForFit.h.

References theWireId.

Referenced by operator<(), and operator==().

{ return theWireId; }

pair< bool, bool > DTHitPairForFit::isCompatible	(	const LocalPoint &	posIni,
		const LocalVector &	dirIni
	)		const

check for compatibility of the hit pair with a given position and direction: the first bool of the returned pair is for the left hit, the second for the right one

Definition at line 57 of file DTHitPairForFit.cc.

References SiStripPI::max, min(), mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by digiTime().

                                                               {


    pair<bool,bool> ret;
    LocalPoint segPosAtZLeft  = posIni+dirIni*(theLeftPos.z() -posIni.z())/dirIni.z();
    LocalPoint segPosAtZRight = posIni+dirIni*(theRightPos.z()-posIni.z())/dirIni.z();
    float dxLeft  = fabs(theLeftPos.x() - segPosAtZLeft.x());
    float dxRight = fabs(theRightPos.x() - segPosAtZRight.x());
    float exx = sqrt(theError.xx());
    // if both below 3 sigma, return both
    // if both at 10 sigma or above, return none
    // if one is below N sigma and one above, for 10>=N>=3, match only that one, otherwise none
    if (std::max(dxLeft, dxRight) < 3*exx) {
        ret = make_pair(true,true);
    } else if (std::min(dxLeft, dxRight) >= 10*exx) {
        ret = make_pair(false,false);
    } else {
        float sigmasL = floorf(dxLeft/exx), sigmasR = floorf(dxRight/exx);
        ret.first  = ( sigmasL < sigmasR );
        ret.second = ( sigmasR < sigmasL );
    } 
    return ret;
}

LocalPoint DTHitPairForFit::leftPos ( ) const

inline

Returns the position in the layer r.f. of the left rechit.

Definition at line 49 of file DTHitPairForFit.h.

References theLeftPos.

Referenced by operator<<().

{ return theLeftPos; }

LocalPoint DTHitPairForFit::localPosition

(

DTEnums::DTCellSide

s

)

const

Returns the local position in the layer.

Definition at line 47 of file DTHitPairForFit.cc.

References Exception, DTEnums::Left, and DTEnums::Right.

Referenced by operator<().

                                                                   {
  if (s==DTEnums::Left) return theLeftPos;
  else if (s==DTEnums::Right) return theRightPos;
  else{ 
    throw cms::Exception("DTHitPairForFit")<<" localPosition called with undef LR code"<<endl;
    return LocalPoint();
  }
}

LocalError DTHitPairForFit::localPositionError ( ) const

inline

Definition at line 55 of file DTHitPairForFit.h.

References theError.

{ return theError; }

bool DTHitPairForFit::operator<

(

const DTHitPairForFit &

hit

)

const

define the order by increasing z

Definition at line 82 of file DTHitPairForFit.cc.

References id(), DTEnums::Left, localPosition(), and PV3DBase< T, PVType, FrameType >::x().

Referenced by digiTime().

                                                                {
  //SL if same layer use x() for strict ordering
  if (id()==hit.id())
    return (theLeftPos.x() < hit.localPosition(DTEnums::Left).x());
  return (id() < hit.id());
}

bool DTHitPairForFit::operator==

(

const DTHitPairForFit &

hit

)

const

Definition at line 89 of file DTHitPairForFit.cc.

References digiTime(), and id().

Referenced by digiTime().

                                                                 {
  return  (id() == hit.id() && fabs(digiTime() - hit.digiTime()) < 0.1 );
}

LocalPoint DTHitPairForFit::rightPos ( ) const

inline

Returns the position in the layer r.f. of the right rechit.

Definition at line 52 of file DTHitPairForFit.h.

References theRightPos.

Referenced by operator<<().

{ return theRightPos; }

Member Data Documentation

float DTHitPairForFit::theDigiTime

private

Definition at line 80 of file DTHitPairForFit.h.

Referenced by digiTime().

LocalError DTHitPairForFit::theError

private

Definition at line 78 of file DTHitPairForFit.h.

Referenced by localPositionError().

LocalPoint DTHitPairForFit::theLeftPos

private

Definition at line 76 of file DTHitPairForFit.h.

Referenced by leftPos().

LocalPoint DTHitPairForFit::theRightPos

private

Definition at line 77 of file DTHitPairForFit.h.

Referenced by rightPos().

DTWireId DTHitPairForFit::theWireId

private

Definition at line 79 of file DTHitPairForFit.h.

Referenced by id().